FLOOD04092

• County: Delta
• Community: Delta
• Basin: Gunnison
• Title: Pre-Disaster Flood Hazard Mitigation Plan
• Date: 2/1/2002
• Prepared For: Delta
• Prepared By: CWCB
• Floodplain - Doc Type: Flood Mitigation/Flood Warning/Watershed Restoration

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d. Future DeveloDment:

In the growth along the river we discourage building in certain areas
of the 100 year floodplain. Following are some of the tools we use:

On the new North Delta sewer line extension it is illegal to hook a new
structure to the sewer if in the floodplain. This will limit growth on the north side of the
floodplain. The City owns much of the ground on the south side of the floodplain,
downstream of the Hwy 50 bridge.

We have floodplain ordinances controlling the placement of structures in and
around the 100 year floodplain.

We are working on a multi-discipline plan for the river corridor which looks
at environment, growth, flooding, and mitigation projects. This plan identifies ground
which could be considered for flood easements, what properties may be considered
candidates for a buy-out program, and which properties are in need of further protection.

e. Problem Statement: I) Areas with the greatest number of buildings at risk. We
have two concentrations of buildings in and around the floodplain. The first is
where the Hwy 50 bridge crosses the river. With both businesses and residents in
close proximity to the river this area has one of the highest potentials for loss of
property and possibly lives. The second area of building concentration is along
Hwy 348 where there are a number of homes.

2) Areas with deepest flood depths - The area of potentially deepest water is along
the Gunnison River. The City is forced to close trail systems during high water
to keep areas of inundation unused.

3) Areas of high velocity flood flows - Greatest flow rates occur near and under the
Hwy 50 bridge. The bridge has necked the river down and raised the base
elevation of the stream bed just upstream of the bridge. The gradient is
concentrated at this area ofthe bridge, increasing velocities.

4) Areas of potential problems - In flood flows we keep a close eye on the Hwy 50
Bridge due to the potential for debris and trees to become lodged under the
bridge. In 1993, there was a large cottonwood tree stuck under the bridge,
gathering debris until it was removed. We are concerned that reduced flow
under the bridge would cause flooding up stream and could put too much
structural stress on the bridge itself.

5) Public infrastructure - Weare concerned about protecting the park and trail
improvements along the river. In 1993 we lost 2,500 feet of trail when the south
bank of the Gunnison was washed into the river. We also have high degrees of